Polarized relay



Sept. 15, 1953 s. D. VIGREN ET AL POLARIZED RELAY Filed May 51, 1951 /4a25 I50 //a //b A56 m;

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2 Sheets-Sheet l INVENTORS Rolf HI "7 Zane/er Sept. 15, 1953 Filed May31. 1951 S. D. VIGREN ET AL POLARIZED RELAY BY I Patented Sept. 15, 1953POLARIZED RELAY *Sten Daniel Vigren, Stockholm, Per Harry EliasClaesson, Jakobsberg, and Rolf .Alb'i'n Zander,

Stockholm, Sweden Application May 31, 1951, SerialNO. 229,058 In SwedenFebruary "16, .1949

(C1. ZOO-=93) 2 Claims. 1

I The present invention relates to polarized relays .ot the typecomprising :a pivoted armature moving in the space between two oppositepoles or va controlling magnetic circuit provided with a winding coil,and one or more permanentmagnets for so polarizing the armature, that itwill be operated in dependance of the direction of current through thewinding coil. Relays of this type are used for instance in telegraphreceiving and repeater devices and for other purposes when a vibratoryarmature movementfis required :or when the armature shall be operatedfor current of one predetermined direction only or in one direction from.a middle position "by current of one direction and in the otherdirection from said middle position .by current of the "reversedirection.

it is important, "that relays of this kind are very rapid in operationand to this end the mornent of inertia of the armature shall be as smallas possible. On the other hand the contacts 0'! the relay will have tobe so located as "to permiteasy accessibility for adjustment andinspection, and in devices hitherto known this has been possible "toachieve only by arranging the annatureas a two-armed lever having itscontact end and the end actuated by the controlling magnetic on eitherside of it's pivotal axis. 'Such an arrangement will, however, inpractice cause the. mass of the armature to be greater than wanted; andthe contacts will be subject to considerable detrimental forces at theoscillatory movement of the armature.

-One object of this invention is to provide a polarized relay of thetype described above having its components so mutually arranged, thatthe use of an armature in the form of a onearmed lever is made possiblewithout obstructing the accessibility of the contacts and that the relaywill be highly sensitive, rapid andsafe in operation. I 7

Another object of the invention is to provide a polarized relay, whichis operable in steps in dependence of different current strengths in therespective current directions.

These and other objects and features of the invention will appear fromthe following description of a few embodiments of the invention inconnection with thea'ccompanying drawings in which:

Fig. 1 shows a polarized relay according to the invention in plane view.i Fig. 2 shows the same relay in side view. I

3 shows in simplified form a similarre lay provided with contact;damping means.

Fig. 4-. shows the relay of Fig. 3 in side view.

Fig. 5 is a modified contact damping device.

In the embodiment according to Figs. 1 and 2 the magnetic circuit of thecontrolling or operating flux comprises a magnetic core I, tw'o polepieces 2 and 3, which are connected with the magnetic core, and aportion of a pivoted armature "4, which is movable in its transversaldirection in an air gap confined by pole faces at the ends of the polepieces 2 and 3. The magnetic circuit of the polarizing circuit isdivided into two portions or branches, each extending through apermanent magnet '5 or 6 respectively via air gaps through a portion ofthe pole piece 2 or 3 respectively and through the armature in itslongitudinal direction. The last mentioned portion of each pole piece 2,3 will thus form a common path of the controlling and the polarizingfluxes.

The controlling flux is effected by means of an energizing coil I.

The armature 4 is in a manner known per se pivoted by means of atransversal leaf spring member 8, which is fixed by screws on one handtoa projection 37 on the armature 4 and on the other hand to a holdingmember 9 being in turn secured to the base plate ID of the relay. Themiddle of the spring 8 "is affixed to a lateral projectionof thearmature. The pole pieces 2 and 3 as well as the magnets 5 and 6 areclamped against the base plate and kept in the desired relativepositions by means of screws in the said holding member 9. y

Two "contain; springs in, I I-b are riveted to the armature andinsulated therefrom by means 01' washers T2 of insulating material,which contact springs in a manner know-n per se are bent-at their freeend so as to form portions abutting against each other having thepurpose of serving as damping means. The end positions of the motion ofthearma-ture is determined by means oi adjustable screws ltd, lilo,which are screwabiein pieces [4a, 'Mb of non-magnetic material. In thepieces Ma, Mb there are also buffer devices i5a, I53, by which it ismade possible to have the armature stand in a middle or any otherposition between the end positions of the -armatu're as determined byscrews I5z, 1517. Each hufier device comprises a screw 16 screw able inpiece M at the inner end of a here through said piece, at the other endof which another screw 1'! is inserted. A pin l8 passes through acentral bore in s rew 18 and is guided in another bore in sicrewl 'l "soas tobe slidably movable in its longitudinal direction. The pin I8 ispressed in a direction towards the armature by means of a pressingspring I9 acting between -the screw I1 and a collar 20 on the pin I8,Which collar abuts against the inner end surface of the screw I6 andthus determines the normal position of the pin l8. The end portion 2| ofthe latter abuts against the armature when this is attracted towards thebuffer device, and if the attracting force is caused merely by thepermanent magnet flux it is not capable of compressing the pretensionedspring l9. On the other hand the pre-tensioning is so chosen that arelatively small amount of controlling magnetic flux acting in thecontemplated direction is required to subdue the counteracting force ofthe spring I9. It will be easily understood that the normal position ofthe armature can be readily adjusted by the screws l6 and the pretensionof springs I9 is adjustable by turning screw H.

In the shown embodiment the armature operates an additional pair ofcontacts comprising contact members 22a, 22b conductively or insulatedlyfixed to the armature. These contact members are cooperating withcountercontact members 23a and 23b respectively consisting of leafsprings being pre-tensioned to abut against stop members 24a, 24b with apredetermined pressure. Thus the armature may be operated in eitherdirection in two steps, first closing the contacts at 23a or 23brespectively at a comparably small number of ampere turns, and then thecon-- tacts at |3a or |3b respectively when the energization isincreased.

The different adjusting screws [3, l6 and I! are lockable in theirpositions by means of locking screws 25, 26 and 21 respectively.

At the portion where the armature has passed the pole pieces 2 and 3 itsarea may be materially reduced so that its mass becomes small and the 1operation speed of the relay is correspondingly increased. This frontportion of the armature may be formed as a tongue, the width of whichonly is determined by the fact, that it shall withstand the contactpressure and that it shall not come into resonance at the highestoperation frequency of the relay, which will be about 2500 c./s.

The mass of the armature may be further reduced by the choice of asuitable material, preferably electrolytic iron or iron having a carbonproportion less than 0.015%. Another suitable material is iron alloyedwith about 50% cobalt, so-called permandur. Generally the knee value ofthe magnetization curve should be at least 15,000 gauss. With knee valueis meant the value defined by the point of intersection between thesaturation asymptote in the magnetization diagram and the tangent to themagnetization curve at the point representing the maximum permeability.Certainly such magnetic materials do not have so high a permeability asfor instance Permalloy, but since the knee value of this material isabout twice that of Permalloy, the armature needs be only half as thick,and accordingly the controlling flux can be forced through the armatureby a comparably small number of ampere turns, provided the saturation ofthe magnetic circuit of the permanent flux is not too high.

In the embodiment according to Figs. 3 and i the magnetic circuits ofthe relay shown in Figs. 1 and 2 are unchanged and, therefore, shownschematically only, whilst the contact devices are modified and providedwith damping means according to the invention. Only one set of contactand damping devices is shown on one side of the armature, although twosuch sets preferably are symmetrically arranged relative to armature 4.

A contact 28 is rigidly fixed to the armature 4 and cooperates with acountercontact 29 attached to a leaf spring 30 in front of which anadditional leaf spring 3| is arranged in juxtaposed relation to spring30 so as to resiliently press against the same. The springs 30 and 3|are commonly attached to a holding piece 32 by means of fastening screws33 and 34. The end portion of the spring 30 is bent into an angle to themain portion of the spring and abuts at this end portion against a body35, preferably a roll, or the like, of insulating material inserted in arecess connected with a threaded bore through the holding piece 32, inwhich an adjusting screw 36 is screwable. The end portion of the leafspring 3| is bent into the same angle as the corresponding portion ofspring 30, so that the pressure exerted by spring 3| is concentrated tothe bent end portion of spring 30. The latter carrying the contactmember 29 will thus be pressed between the roll 35 on one side and theend portion of spring 3| on the other side. By means of the adjustingscrew the roll 35 may be displaced in its recess and the position ofthecontact 28 may thus be adjusted. An important feature of the showndevice is that the main portion of spring 30 extends parallel with thearmature whereby only a small sliding action arises between the contacts28 and 29. The surfaces of the latter become often rough and unevenafter having been in use for some time, and if the main portion ofspring 30 then forms a relatively large angle to the longitudinal axisof the armature, as is the casein similar known devices, the resilienceof the spring 30 becomes irregular at the contact point and consequentlythe break and closure functions become unsafe. In practice it hasproved, that the portion of the spring 30 extending between the fixed-inend and the bend ought to be comparably stiff, and this spring is,therefore, preferably weakened by a cut-out portion adjacent to thepoint, where the spring 3| abuts against the spring 30. The modificationaccording to Fig. 5 differs from the one shown in Figs. 3 and 4 only inthat the pressing spring 3| is fixed to a holding piece 32 so as toextend from above and engage the spring 30 close to the contact 29.

What we claim is:

1. A polarized relay comprising an armature, means for defining apivotal axis of said armature, a magnetic circuit comprising poleprojections forming an air space confined by pole faces facing oppositesides of said armature and a core having an energizing coil for theenergization of said magnetic circuit said armature extendingsubstantially perpendicularly to said core and having its pivotal axissituated adjacent to the middle portion of said coil, said poleprojections further extending substantially parallel with said core andbeing spaced apart from said coil, pieces connecting said core with saidpole projections and two permanent magnets being each magneticallycoupled with its one pole to each one of said pieces and having theirother poles magnetically coupled to said armature at a portion adjacentto the pivotal axis of the latter, which permanent magnets extendsubstantially parallel with said core in the spaces between said coiland said pole projections, and contact members operable by saidarmature, said pole face and said contact members being situated on thesame side of said pivotal axis.

2. A polarized relay according to claim 1, comprising means for keepingsaid armature in a middle position between said pole faces innonenergized condition, and two sets of contact members on either sideof the armature one of the said sets of contact members being adapted tobe closed at a smaller deviation of the armature from said middleposition than the other, spring means for resiliently supporting acontact member of the first-mentioned set of contact members, and stopmeans for defining one end position of the last-mentioned contact memberin a direction towards the armature, said spring means beingpre-tensioned to abut with a predetermined pressure against said stopmeans.

STEN DANIEL VIGREN. PER HARRY ELIAS CLAESSON. ROLF ALBIN ZANDER.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Name Date Phelps Jan. 12, 1886 Dean May 18, 1909 Snyder Jan. 14,1930 Lum Mar. 24, 1936 Garpenter Dec. 3, 1946 Carpenter Oct. 24, 1950FOREIGN PATENTS Country Date Sweden Apr. 10, 1945 Great Britain July 9,1948 Germany Dec. 22, 1937 Germany Oct. 20, 1941

